60 
THE CULTIVATOR. 
THE « YELLOWS” IN PEACH TREES. 
Mr. Tucker: Sir —About the year 1795, peach trees, 
in the neighborhood of Philadelphia, began to die with¬ 
out any apparent cause. Soon after, they began to per¬ 
ish in like manner more and more remotely from that 
city. By 1810, few peach trees were left alive in the 
State of New-Jersey. They began to die around New- 
York about 1801, and in the State of Connecticut, about 
1815. The unknown cause of this strange death of trees, 
before considered as hardy as other fruit trees, has been 
termed the <£ Yellows and has been called a disease, in 
analogy to those epidemics which at times lay waste hu¬ 
man life. It is, perhaps, the first and only instance of 
any affection in the vegetable kingdom, that can be called 
with propriety, disease. It has all the appearance of be¬ 
ing constitutional; bearing no resemblance to the decline 
and decay caused by bad soil, unsuitable temperature, or 
local injuries. 
Hitherto, all efforts to discover the cause of this fatal 
malady, have been made without success. What produ¬ 
ces the “ Yellows,” is as much unknown as what produ¬ 
ces the cholera. One circumstance has doubtless preven¬ 
ted a very general and thorough search for the cause of 
the Yellows. Every where we have occasionally seen 
an insect (iEgeria excitiosa) that eats into the bark of 
peach trees, near the surface of the ground. Whenever 
a person discovers this insect at work, he imputes the 
death of his trees to that. Most persons stop here, mere¬ 
ly looking about for some mode of keeping out or de¬ 
stroying the peach worm. Now the effects of the Yel¬ 
lows are as different from those of the boring of the peach 
worm, as the small pox is different from the cut of a 
knife. If every body could be made aware of this dif¬ 
ference, research would be universally awakened, and 
receive a direction that might lead to the most valuable 
results. A great step will be gained, if a hundred thou¬ 
sand readers of the “ Cultivator” would all understand 
alike what is meant by the term Yellows in peach trees; 
would all understand distinctly, that it does not mean 
peach worm. For (his reason I deem it of great impor¬ 
tance to present in the Cultivator a clear, unmistakeable 
description of this fatal disease. 
There are two marks or symptoms, by which the pre¬ 
sence of the disease is indicated. One is, the shooting 
out from the body or limbs of the tree of very small, 
slender shoots, about the size of a hen’s quill. The 
leaves upon these shoots are commonly destitute of green 
color, as if blanched, or as if grown in a dark cellar; 
and like the shoots which bear them, are of diminutive 
growth—rarely exceeding an inch in length. These 
shoots do not usually start from the common, visible 
buds at the points where the leaves join the stem, but 
from unseen latent buds in the bark of the trunk or large 
branches. The other symptom is, the ripening of the 
fruit two to four weeks before its natural season of matu¬ 
rity. Most generally also, the fruit, whatever be its na¬ 
tural color, is more or less spotted with purplish red 
specks. If shoots, such as are above described, appear 
upon a tree, or without them, if the fruit upon any part 
of it (not wormy) ripens before the proper time, it ma) 
be certainly known that the tree has the Yellows. 
These are not the only marks or symptoms of the dis¬ 
ease; but they are those which are the most readily dis¬ 
covered. The ordinary leaves of the tree, or at least 
those upon the diseased portion of it, commonly undergo 
a slight change of color. Instead of a bright glossy 
green, they take on a dull yellowish tinge. The wood 
also, when the disease is considerably advanced, becomes 
unelastic, so that its branches, when moved by the 
wind, instead of the graceful waving of health, have a 
stiff, jerking motion. These two last mentioned symp¬ 
toms will not readily be seen but by a practiced eye. 
What I have further to say concerning this disease, may 
most conveniently be stated in separate sections. 
Sec. 1. The slender shoots spoken of above, do not ap¬ 
pear to ripen their wood perfectly. They continue in a 
great degree herbaceous till frost comes. For (his rea¬ 
son, or because no buds are formed on them, (hey perish 
the succeeding winter. 
Sec. 2. The fruit may exhibit marks of disease, when 11 
the other symptom (slender shoots) is not discoverable. 
But, on the other hand, I have never seen the slender 
shoots on any part of the tree, without the fruit, if there 
was any, being affected. 
Sec. 3. The fruit, the first season of attack, usually 
grows to its proper size. The second season, it is uni¬ 
formly small—not more than a half or a quarter of its 
proper size. 
Sec. 4. Whatever be the natural color of the fruit, red, 
yellow, white or green, it is more or less, when diseas¬ 
ed, colored with purplish red; generally in specks or 
coarse dots. The flesh, quite (o the stone, is often col¬ 
ored, and most deeply around the stone. By the colored 
specks, a person may easily distinguish by the eye, dis¬ 
eased from healthy fruit, as it is offered in market. 
Sec. 5. The taste of diseased fruit cannot be exactly 
described, for want of appropriate words. The word in¬ 
sipid almost describes it. There is an absence of all 
agreeable flavor, and there is not much that is disagree- 
ble. A few sorts retain, in spite of disease, some of their 
exquisite peach flavor. 
Sec. 6. In the first summer of disease, it is not always 
that the whole tree appears affected. The slender shoots 
may show themselves on one branch only, the rest of the 
tree having every appearance of health. In like manner, 
the fruit upon one branch may ripen four weeks too soon, 
upon another two weeks too soon, and upon the rest of 
the tree at the natural time. The second season, all the 
fruit will ripen three or four weeks too soon. 
Sec. 7. The tree sometimes dies the next year after the 
apearance of the disease, and sometimes lingers along 
with a feeble life for two or three years. Sooner or la 
ter however, it is overcome by the disease. I have ne¬ 
ver known, nor have I heard authentically, of any tree 
recovering from it. 
Sec. 8. Soil, whether of clay or sand, whether moist 
or dry, whether cultivated or in grass, manured or un¬ 
manured, does not appear to me, clearly, either to in¬ 
crease or diminish the liability to disease. 
Sec. 9. Trees standing in exposed and sheltered situa¬ 
tions, walled and in open ground, on hills and in valleys, 
seem alike and equally liable to the Yellows. 
Sec. 10. Trees standing in places where people are 
passing to and fro very often near them, though not ex 
empt from the disease, appear less liable to it than oth 
ers. This is strikingly exemplified in the city of New- 
Haven, where trees standing close by the sidewalks, out¬ 
live all others. The same fact I have observed upon my 
own premises. 
Sec. 11. Luxuriant and vigorous growth is no protec¬ 
tion against the disease. Trees have grown 5 feet in the 
same season when they have shown in the body and fruit 
the marks of the Yellows. On the contrary, slow growth 
is perhaps, (I cannot speak confidently) favorable to 
health. On this point I give the following fact. Five 
years ago this fall, I dug a hole in my meadow, a foot 
square and 18 inches deep, threw back the earth, and 
planted a peach stone. It came up next spring, and has 
grown very slowly. It is now only 45 inches high, but 
perfectly healthy; while every other tree planted at the 
same time in my garden, a few rods offj grew vigorous¬ 
ly, bore fruit, took the Yellows, and have been dug up. 
Sec, 12. When the disease commences in a garden or 
orchard containing a considerable number of trees, it 
does not attack all at once. It breaks out in patches, 
which are progressively enlarged, till eventually all the 
trees become victims to the malady. Thus in an orchard 
of two and a half acres, all the trees were healthy in 
1827. The next year 2 trees on the west side of the or¬ 
chard, within a rod of each other, took the Yellows, In 
1829, six trees on the east side of the orchard were at¬ 
tacked; five of them standing within a circle of four rods 
diameter. In 1830, fifteen more were attacked; fourteen 
of which stood within a circle of four rods diameter, A 
similar fact is now apparent in my neighborhood. A 
fine lot of 200 young trees, last year in perfect health, 
now show disease in two spots, near the opposite ends of 
the lot, having exactly six diseased trees in each patch, 
contiguous to each other; while all the other trees are 
free from any marks of disease. 
Sec. 13. Young trees, even in the first summer of their 
